multi-loop lowering bug

[StefanKarpinski]

Reported here #330 (comment):

julia> for x=1:4, y=1:2
          println( (x,y) )
          (y,x) = (x,y)
       end
(1, 1)
(1, 2)
(2, 1)
(1, 2)
(3, 1)
(1, 2)
(4, 1)
(1, 2)

Expected (x and y reset):

(1, 1)
(1, 2)
(2, 1)
(2, 2)
(3, 1)
(3, 2)
(4, 1)
(4, 2)

Seen on both 0.6.1 and recent master (00e3a9f).

[martinholters]

I think this is a dup of #330, see #330 (comment).

[StefanKarpinski]

We'll close if it is a dup 👍

[JeffBezanson]

Closing as dup.